State cops can track residents' cellphones

Wisconsin officials mum on use of warrants, data related to Stingray device

Mar. 28, 2014

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Stingray – how it works

Stingray cell phone tracking technology is closely guarded by Harris Corp. and the law enforcement agencies who buy the device, but recent public records released to Gannett Wisconsin Media and other news organizations have shed some light on how it works. The suitcase-sized Stingray masquerades as a cell phone tower and tricks all cell phones within a roughly one-mile radius into connecting to it. Cell phones are constantly seeking out area towers in search of the strongest wireless signal, and phones mistake the Stingray for a tower. Police typically use the technology to locate a specific phone, but the device captures location and identification information on every phone within range. The Stingray — typically accompanied by a laptop to receive the data and a directional antenna — is generally installed in a vehicle to allow use anywhere. Since it uses the phones’ cellular connection, the Stingray can track any phone, not just the more advanced phones equipped with GPS.

About this report

As part of a USA TODAY/Gannett investigation on the use of Stingray cell tracking devices around the country, the Gannett Wisconsin Media Investigative Team sought records from the state Department of Justice on any dealings with Harris Corp., the Florida-based Stingray manufacturer. A public records request was filed Nov. 7 for all contracts and funding requests involving Harris, but no documents were turned over for three months despite an email from DOJ spokeswoman Dana Brueck on Nov. 26 saying the request was “nearing completion.” DOJ turned over 207 pages of heavily redacted documents in mid-February, a week after Bob Dreps, an attorney for Gannett Wisconsin Media, alerted the DOJ that Gannett was prepared to pursue court action due to the lengthy delay. A letter from Assistant Attorney General Kevin Potter said the redactions — which included the names of various technology and some descriptions, prices and quantities — were needed to keep suspects unaware of how to avoid detection and to ensure the safety of law enforcement. It said disclosure could also violate federal law since the Homeland Security Act of 2002 bars disclosure of information that “relates to the ability to prevent, interdict or disrupt terrorist activity.” However, an unredacted 2012 purchase requisition confirmed the DOJ’s ownership of at least one Stingray as it explained how the DOJ used cell tracking devices and referenced the need to upgrade the agency’s Amberjack antenna, an accessory used with the Stingray. Redacted DOJ memos and invoices show an “electronic tracking system” was purchased from Harris in 2006 for $152,626, then upgraded in 2009 and again in 2013. A 2013 memo references an “electronic surveillance” system that uses cell networks and seeks an upgrade to a device purchased in late 2004. It is not clear if that is referencing a second Stingray device or another similar piece of technology, or if it simply misstates the original purchase date. Court records stemming from a 2009 murder in Milwaukee showed Milwaukee police use a Stingray as well. Documents tied to a federal grant and an invoice obtained by Gannett Wisconsin Media show Milwaukee police paid $107,500 this February to upgrade its Stingray and get training in Florida on how to use it.

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Police in Wisconsin have at least two devices that secretly track cellphone locations in real time to target suspects or missing persons — technology that simultaneously mines data from hundreds or thousands of unsuspecting people nearby.

The devices — known by the trade name Stingray — raise an array of concerns for privacy advocates because law enforcement officials won’t say how often the device is used, how the data is used or kept, or whether they get a warrant from a judge before using it.

“We have very powerful technology that has very important consequences for our privacy, but we don’t have the kind of transparency necessary to kind of understand what the contours of the issue are,” said Byron Lichstein, an attorney arguing a Wisconsin Supreme Court case over whether a warrant to use a Stingray in Milwaukee was sufficient. “Even if the targeted information is narrow, the amount and private nature of the information that can be collected is pretty striking.”

Law enforcement officials declined interview requests and redacted references to the Stingray in public records requested by the Gannett Wisconsin Media Investigative Team.

However, documents show the devices have been used for years by the Wisconsin Department of Justice and the Milwaukee Police Department. The DOJ device has been in use since at least 2006 and is loaned to federal, state and local agencies for use throughout Wisconsin and neighboring states.

The suitcase-sized Stingray masquerades as a cell tower to trick cellphones into connecting to it. It can show police phones within a mile or more, depending on terrain. Records show the DOJ Stingray cost more than $150,000, and the DOJ and Milwaukee police both purchased upgradepackages that topped $100,000.

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A Stingray is not believed to intercept the content of calls or text messages. But it captures location details and, possibly, the numbers with which a given phone is communicating, according to court records and published reports.

“It’s hard to know how all the information is going to be used once it’s collected so that’s why you need limits on what can and can’t be collected,” said Lichstein, a clinical associate professor at the University of Wisconsin Law School.

The Wisconsin Legislature passed a bill in February requiring warrants to use cell phone tracking technology in most cases. But the legislation — which has yet to be signed by Gov. Scott Walker — would place fewer limits on cellphone tracking than state law requires for traditional search warrants, which an American Civil Liberties Union attorney calls “worrisome.”

Device sparks privacy worries

State Sen. Glenn Grothman, the senate’s lead sponsor of the cellphone tracking bill, said he is disturbed by the capabilities of the Stingray.

“We’re headed to the point where the government knows where you are at any time of the day or night, and we don’t want to be there,” said Grothman, R-West Bend. “The people who push these devices of course will always say that you can trust the government — they will never abuse their power. But a lot of our Constitution is based on the idea that you can’t trust the government with unlimited power.”

Nathan Wessler, an attorney with the ACLU in New York, said the Stingray’s broad swath could run afoul of the Fourth Amendment protections against unreasonable search and seizure.

“It’s vital that anytime police want to use one of these devices they go to a judge first, seek a warrant and fully explain to the judge exactly what the capabilities of this technology are, so a judge can understand how invasive it can be,” Wessler said, noting that a Stingray forces phones to report their location and a unique ID number, even from inside a private home.

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It appears obtaining a warrant is common practice for Stingray use here, based on testimony in the Milwaukee Stingray case. A Milwaukee police officer testified in 2011 that his department always obtains court orders before using the Stingray, and Assistant Attorney General Jeffrey Kassel told the Wisconsin Supreme Court in October that DOJ policy is to “get a warrant unless there’s exigent circumstances,” meaning a life or death situation.

Police in other states have often used the device without warrants, including more than 200 times in Florida since 2010, according to court testimony. A Minnesota agency said in 2011 warrants aren’t needed because a cell tracking device “does not intercept communication.”

“While we place a premium on the value of technology that allows law enforcement to help solve crimes and bring justice to those whom commit them, we genuinely appreciate the public’s legitimate need to live free of unreasonable intrusions into their constitutional rights,” Palmer said.

Officials won't discuss device

Specifics on the Stingray are hard to come by since the manufacturer, Florida-based Harris Corp., won’t discuss its technology and requires customers to sign non-disclosure agreements. Invoices for upgrades purchased by Milwaukee police and the DOJ in the last year bar disclosure without giving Harris “timely notice and the opportunity to challenge such disclosure under applicable laws.”

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DOJ spokeswoman Dana Brueck declined to answer questions about the Stingray, and the DOJ redacted documents related to Harris Corp. in response to a public records request from Gannett Wisconsin Media, obscuring what devices were purchased, and in some cases the quantity and cost as well. The DOJ said disclosure would reveal “confidential law enforcement and investigative techniques.”

Milwaukee Police Department spokesman Lt. Mark Stanmeyer did not return phone calls or emails seeking comment for this story. Harris spokesman Jim Burke declined to answer questions about the Stingray “because of the nature of our customers and the technology.” Harris sells surveillance devices for law enforcement and military use.

State Rep. Melissa Sargent, D-Madison, said authorities have a responsibility to publicly discuss the Stingray technology.

“It may end up causing me to be relieved to know it’s out there and how it is that they use it, but when they don’t share that information I think people automatically jump to the scariest and worst scenarios,” said Sargent, who co-authored the bill on cellphone tracking.

Wessler noted it is “no longer a secret” that the Stingray is used since officials in other states have done interviews discussing it.

An investigation by USA TODAY and Gannett media around the country found at least 25 police departments outside Wisconsin own a Stingray. More than 30 other agencies refused to say whether they own one.

The FBI also has Stingray devices and coordinates their use with other agencies around the country, according to documents obtained by the Washington, D.C.-based Electronic Privacy Information Center. Spokesman Leonard Peace in the FBI’s Milwaukee office declined to say whether the federal agency uses Stingrays in Wisconsin.

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Documents shed light on Stingray use

An unredacted DOJ purchase requisition from December 2012 says special agents with the agency’s Division of Criminal Investigation used cell tracking equipment in recent years “to identify and track cellular phones” at marijuana grow operations in northern and central Wisconsin.

The requisition said agents also followed the growers to safe houses and used cell-tracking equipment “to identify other co-conspirators based on their cellular phones.” The document confirmed the device was a Stingray, referencing the need for an upgraded Amberjack antenna, an accessory used with Stingray systems.

A March 2013 memo didn’t reference the Stingray directly but saidHarris surveillance equipment has resulted in hundreds of rescues and arrests for the DOJ. A 2009 memo regarding upgraded cell tracking equipment said it is used “in critical or high-profile cases such as Amber Alerts, kidnappings or homicides.”

But local officials say the technology is also used in less serious cases.

Shawano County Sheriff’s Department Detective Chris Gamm said he isn’t aware of his agency using a Stingray in recent years, but Shawano County was alerted the DOJ has a vehicle-mounted device that could pose as a cell tower and be used, for example, to locate a person who made dozens of prank 911 calls.

Winnebago County Sheriff John Matz said the DOJ used cell-tracking technology — though he didn’t know the name of the device — several years ago to locate a man wanted on a felony warrant who had threatened a family member.

High court to rule on Stingray warrant

In the case pending before the Wisconsin Supreme Court, a convicted murderer is arguing that a court order authorizing the use of a Stingray to track him down was improper.

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Police turned to cell-tracking technology after surveillance cameras showed a man purchasing a cellphone, then walking out to a parking lot and shooting a man in the back of the head in Milwaukee on June 9, 2009, court records show.

After obtaining a court order, investigators used data from the cellphone provider to narrow the location of the phone to a specific neighborhood. Police then used a Stingray in a vehicle to determine the phone was in an apartment on the city’s north side. Police arrested Tate there seven hours after the shooting.

Tate, 29, of Milwaukee, was convicted of homicide and sentenced to 43 years in prison. Circuit court and appeals judges ruled the warrant and tracking were proper, but Tate then appealed to the state Supreme Court.

In oral arguments in October, Lichstein, who was appointed to represent Tate, argued the warrant was invalid because it didn’t detail how locating the cellphone would constitute evidence of the crime. He said warrants can’t be issued merely to locate a person.

Kassel, the assistant attorney general, argued it’s constitutional to use a cell tracker with a warrant to locate a suspect, with no guarantee the location will also provide evidence of a crime.